1 /* 2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 /* 27 * This file is available under and governed by the GNU General Public 28 * License version 2 only, as published by the Free Software Foundation. 29 * However, the following notice accompanied the original version of this 30 * file, and Oracle licenses the original version of this file under the BSD 31 * license: 32 */ 33 /* 34 Copyright 2009-2013 Attila Szegedi 35 36 Licensed under both the Apache License, Version 2.0 (the "Apache License") 37 and the BSD License (the "BSD License"), with licensee being free to 38 choose either of the two at their discretion. 39 40 You may not use this file except in compliance with either the Apache 41 License or the BSD License. 42 43 If you choose to use this file in compliance with the Apache License, the 44 following notice applies to you: 45 46 You may obtain a copy of the Apache License at 47 48 http://www.apache.org/licenses/LICENSE-2.0 49 50 Unless required by applicable law or agreed to in writing, software 51 distributed under the License is distributed on an "AS IS" BASIS, 52 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 53 implied. See the License for the specific language governing 54 permissions and limitations under the License. 55 56 If you choose to use this file in compliance with the BSD License, the 57 following notice applies to you: 58 59 Redistribution and use in source and binary forms, with or without 60 modification, are permitted provided that the following conditions are 61 met: 62 * Redistributions of source code must retain the above copyright 63 notice, this list of conditions and the following disclaimer. 64 * Redistributions in binary form must reproduce the above copyright 65 notice, this list of conditions and the following disclaimer in the 66 documentation and/or other materials provided with the distribution. 67 * Neither the name of the copyright holder nor the names of 68 contributors may be used to endorse or promote products derived from 69 this software without specific prior written permission. 70 71 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 72 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 73 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 74 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER 75 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 76 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 77 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 78 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 79 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 80 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 81 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 82 */ 83 84 package jdk.internal.dynalink.support; 85 86 import java.lang.invoke.MethodHandles; 87 import java.lang.invoke.MethodHandles.Lookup; 88 import java.lang.invoke.MethodType; 89 import java.lang.ref.Reference; 90 import java.lang.ref.WeakReference; 91 import java.util.Arrays; 92 import java.util.Collections; 93 import java.util.List; 94 import java.util.StringTokenizer; 95 import java.util.WeakHashMap; 96 import jdk.internal.dynalink.CallSiteDescriptor; 97 98 /** 99 * Usable as a default factory for call site descriptor implementations. It is weakly canonicalizing, meaning it will 100 * return the same immutable call site descriptor for identical inputs, i.e. repeated requests for a descriptor 101 * signifying public lookup for "dyn:getProp:color" of type "Object(Object)" will return the same object as long as 102 * a previously created, at least softly reachable one exists. It also uses several different implementations of the 103 * {@link CallSiteDescriptor} internally, and chooses the most space-efficient one based on the input. 104 * @author Attila Szegedi 105 */ 106 public class CallSiteDescriptorFactory { 107 private static final WeakHashMap<CallSiteDescriptor, Reference<CallSiteDescriptor>> publicDescs = 108 new WeakHashMap<>(); 109 110 111 private CallSiteDescriptorFactory() { 112 } 113 114 /** 115 * Creates a new call site descriptor instance. The actual underlying class of the instance is dependent on the 116 * passed arguments to be space efficient; i.e. if you only use the public lookup, you'll get back an 117 * implementation that doesn't waste space on storing the lookup object. 118 * @param lookup the lookup that determines access rights at the call site. If your language runtime doesn't have 119 * equivalents of Java access concepts, just use {@link MethodHandles#publicLookup()}. Must not be null. 120 * @param name the name of the method at the call site. Must not be null. 121 * @param methodType the type of the method at the call site. Must not be null. 122 * @return a call site descriptor representing the input. Note that although the method name is "create", it will 123 * in fact return a weakly-referenced canonical instance. 124 */ 125 public static CallSiteDescriptor create(final Lookup lookup, final String name, final MethodType methodType) { 126 name.getClass(); // NPE check 127 methodType.getClass(); // NPE check 128 lookup.getClass(); // NPE check 129 final String[] tokenizedName = tokenizeName(name); 130 if(isPublicLookup(lookup)) { 131 return getCanonicalPublicDescriptor(createPublicCallSiteDescriptor(tokenizedName, methodType)); 132 } 133 return new LookupCallSiteDescriptor(tokenizedName, methodType, lookup); 134 } 135 136 static CallSiteDescriptor getCanonicalPublicDescriptor(final CallSiteDescriptor desc) { 137 synchronized(publicDescs) { 138 final Reference<CallSiteDescriptor> ref = publicDescs.get(desc); 139 if(ref != null) { 140 final CallSiteDescriptor canonical = ref.get(); 141 if(canonical != null) { 142 return canonical; 143 } 144 } 145 publicDescs.put(desc, createReference(desc)); 146 } 147 return desc; 148 } 149 150 /** 151 * Override this to use a different kind of references for the cache 152 * @param desc desc 153 * @return reference 154 */ 155 protected static Reference<CallSiteDescriptor> createReference(final CallSiteDescriptor desc) { 156 return new WeakReference<>(desc); 157 } 158 159 private static CallSiteDescriptor createPublicCallSiteDescriptor(final String[] tokenizedName, final MethodType methodType) { 160 final int l = tokenizedName.length; 161 if(l > 0 && tokenizedName[0] == "dyn") { 162 if(l == 2) { 163 return new UnnamedDynCallSiteDescriptor(tokenizedName[1], methodType); 164 } if (l == 3) { 165 return new NamedDynCallSiteDescriptor(tokenizedName[1], tokenizedName[2], methodType); 166 } 167 } 168 return new DefaultCallSiteDescriptor(tokenizedName, methodType); 169 } 170 171 private static boolean isPublicLookup(final Lookup lookup) { 172 return lookup == MethodHandles.publicLookup(); 173 } 174 175 /** 176 * Tokenizes the composite name along colons, as well as {@link NameCodec#decode(String) demangles} and interns 177 * the tokens. The first two tokens are not demangled as they are supposed to be the naming scheme and the name of 178 * the operation which can be expected to consist of just alphabetical characters. 179 * @param name the composite name consisting of colon-separated, possibly mangled tokens. 180 * @return an array of tokens 181 */ 182 public static String[] tokenizeName(final String name) { 183 final StringTokenizer tok = new StringTokenizer(name, CallSiteDescriptor.TOKEN_DELIMITER); 184 final String[] tokens = new String[tok.countTokens()]; 185 for(int i = 0; i < tokens.length; ++i) { 186 String token = tok.nextToken(); 187 if(i > 1) { 188 token = NameCodec.decode(token); 189 } 190 tokens[i] = token.intern(); 191 } 192 return tokens; 193 } 194 195 /** 196 * Tokenizes a composite operation name along pipe characters. I.e. if you have a "dyn:getElem|getProp|getMethod" 197 * operation, returns a list of ["getElem", "getProp", "getMethod"]. The tokens are not interned. 198 * @param desc the call site descriptor with the operation 199 * @return a list of tokens 200 */ 201 public static List<String> tokenizeOperators(final CallSiteDescriptor desc) { 202 final String ops = desc.getNameToken(CallSiteDescriptor.OPERATOR); 203 final StringTokenizer tok = new StringTokenizer(ops, CallSiteDescriptor.OPERATOR_DELIMITER); 204 final int count = tok.countTokens(); 205 if(count == 1) { 206 return Collections.singletonList(ops); 207 } 208 final String[] tokens = new String[count]; 209 for(int i = 0; i < count; ++i) { 210 tokens[i] = tok.nextToken(); 211 } 212 return Arrays.asList(tokens); 213 } 214 215 /** 216 * Returns a new call site descriptor that is identical to the passed one, except that it has some parameter types 217 * removed from its method type. 218 * @param desc the original call site descriptor 219 * @param start index of the first parameter to remove 220 * @param end index of the first parameter to not remove 221 * @return a new call site descriptor with modified method type 222 */ 223 public static CallSiteDescriptor dropParameterTypes(final CallSiteDescriptor desc, final int start, final int end) { 224 return desc.changeMethodType(desc.getMethodType().dropParameterTypes(start, end)); 225 } 226 227 /** 228 * Returns a new call site descriptor that is identical to the passed one, except that it has a single parameter 229 * type changed in its method type. 230 * @param desc the original call site descriptor 231 * @param num index of the parameter to change 232 * @param nptype the new parameter type 233 * @return a new call site descriptor with modified method type 234 */ 235 public static CallSiteDescriptor changeParameterType(final CallSiteDescriptor desc, final int num, final Class<?> nptype) { 236 return desc.changeMethodType(desc.getMethodType().changeParameterType(num, nptype)); 237 } 238 239 /** 240 * Returns a new call site descriptor that is identical to the passed one, except that it has the return type 241 * changed in its method type. 242 * @param desc the original call site descriptor 243 * @param nrtype the new return type 244 * @return a new call site descriptor with modified method type 245 */ 246 public static CallSiteDescriptor changeReturnType(final CallSiteDescriptor desc, final Class<?> nrtype) { 247 return desc.changeMethodType(desc.getMethodType().changeReturnType(nrtype)); 248 } 249 250 /** 251 * Returns a new call site descriptor that is identical to the passed one, except that it has additional parameter 252 * types inserted into its method type. 253 * @param desc the original call site descriptor 254 * @param num index at which the new parameters are inserted 255 * @param ptypesToInsert the new types to insert 256 * @return a new call site descriptor with modified method type 257 */ 258 public static CallSiteDescriptor insertParameterTypes(final CallSiteDescriptor desc, final int num, final Class<?>... ptypesToInsert) { 259 return desc.changeMethodType(desc.getMethodType().insertParameterTypes(num, ptypesToInsert)); 260 } 261 262 /** 263 * Returns a new call site descriptor that is identical to the passed one, except that it has additional parameter 264 * types inserted into its method type. 265 * @param desc the original call site descriptor 266 * @param num index at which the new parameters are inserted 267 * @param ptypesToInsert the new types to insert 268 * @return a new call site descriptor with modified method type 269 */ 270 public static CallSiteDescriptor insertParameterTypes(final CallSiteDescriptor desc, final int num, final List<Class<?>> ptypesToInsert) { 271 return desc.changeMethodType(desc.getMethodType().insertParameterTypes(num, ptypesToInsert)); 272 } 273 }